The development of a control program which controls a vehicle engine, etc. for example includes generally the steps of (a) writing (coding) a control program based on design (control) specifications (control model), (b) verifying (debugging) the presence or absence of abnormality in the written control program, (c) debugging and fitting the debugged control program on a real vehicle (on-vehicle check), and (d) further modifying the control program based on the result of the on-vehicle check.
The recent trend of control program development includes the development of a model base having a step of producing automatically a control program which is written in a programming language from a control model which represents requisite specifications. In this model base development, a control model is simulated with existing software on a computer thereby to test the operational fitness of the control model.
The control program produced automatically from such a tested control model is high in completeness, enabling the reduction of correction of control program at the step of the above item (d). Constructing a control model is easier than writing a control program. Accordingly, adopting the model base development also enables to enhance the efficiency of control program development.
It is possible that an automatically-generated control program can newly provide an execution sequence of processing defined by a control model which may not correspond inherently to the control model.
On this account, adopting the above model base development will encounter the difficulty in the debugging work for the control program which has been produced automatically from the control model and in the debugging work for testing and modifying the fitness of the control model to be used for the automatic generation of control program. This is attributable to the uncertain consistency in execution sequence between the control model and the control program as described above. When any problem is found in one of the control model and the control program in the debugging work, it will be difficult to determine the spot of the other corresponding to the former problematic spot.